This invention relates to, for example, a recording apparatus having a conveying means of a recording medium for transporting the recording medium and recording an image on the recording medium, as well as to a method of transporting sheets of the recording medium in this apparatus. In the embodiments set forth below, a case is described in which the recording apparatus is an ink-jet recording apparatus. However, the invention is applicable also to a recording apparatus using various recording techniques, examples of which are thermal printers, photosensitive printers and laser printers.
A variety of recording media can be used in conventional ink-jet printers. Examples are plain paper, glossy paper, transparent sheets for overhead projectors (OHP), postcards, envelopes and seals. In order to use these recording media selectively, the conventional practice is to provide the apparatus with a feed port for manual insertion of sheets and to accommodate the sheets that are usually used in a paper cassette. Sheets that are used only on a temporary basis are manually inserted from the feed port one sheet at a time. This arrangement has a number of drawbacks.
Specifically, only a single mechanism is provided for stacking and accommodating a plurality of sheets of the recording medium and extracting the stacked recording medium one sheet at a time. As a consequence, if two types of recording media are often used and these two types of recording media are used by frequently switching between them, one type must always be inserted manually one sheet at a time.
In recent years, large numbers of printers of a type capable of handling recording media in the form of large-size sheets have appeared. For example, printers capable of printing on recording sheets of sizes A3 and A2, etc., have become quite common. At the same time, higher definition obtained by raising the recorded pixel density has been accompanied by improved recorded image quality, and this has made possible the widespread use of glossy paper and transparent sheets for the recording of photographic images. These sheets consist of a base material and an ink-absorbing image-receiving layer formed on the base material, and the sheet surface is formed to be much smoother than that of plain paper. When a plurality of such sheets are stacked, therefore, adjacent sheets are more likely to adhere to each other. If a resin material such as a PET (polyethylene terephthalate) film is used as the base material of these sheets, static electricity tends to be produced, causing the sheets to exhibit even greater adhesion to each other. Moreover, the image-receiving layer itself has a greater viscosity than plain paper. Owing to the greater size and higher mutual adhesion of these sheets, it is extremely difficult to feed them stably using the conventional technique in which sheets are separated and fed one at a time by means of a separating roller. Accordingly, the state of the art is such that when recording is performed on sheets of this type, the sheets are set by inserting them manually one at a time. When recording is to be performed on large quantities of such sheets, the operation cannot be performed in an efficient manner.